Program: NOVA | Type: Clip | Aired: 2019-06-10

The 170-Year Search for a Planet Beyond Neptune

Planet Nine’s existence is not the first time astronomers have predicted a planet they couldn’t see. Clyde Tombaugh was looking for Planet X when he accidentally found Pluto. After Voyager 2 flew by Neptune in 1989, new calculations determined there was no Planet X. But three years ago, a disturbance was detected at the far reaches of the Solar System.

PBS’ premier science series helps viewers of all ages explore the science behind the headlines. Along the way, NOVA programs demystify science and technology and highlight the people involved in scientific pursuits.

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The 170-Year Search for a Planet Beyond Neptune